The present invention relates to machinery for manufacturing containers. More specifically, the invention relates to a method for closely coupling machines used to neck metallic can bodies.
Beverages such as beer and carbonated soft drinks are commonly packaged in two-piece cans formed from aluminum material. Two-piece cans are typically manufactured by attaching a circular lid to an open end of a generally cylindrical can body formed by a drawing and ironing process.
The diameter of the open end of the can body may be reduced prior to attaching the lid thereto. Reducing the diameter of the open end facilitates the use of a smaller-diameter lid than would otherwise be possible. The process by which the diameter of the can end is reduced is known as xe2x80x9cnecking.xe2x80x9d
Necking is typically performed in a number of incremental steps, with the diameter of the can end being reduced only slightly in each step. Necking the can end in this manner reduces the potential for the can end to become wrinkled or otherwise distorted as its diameter is reduced.
Necking can be performed in several different manners. For example, a process known as xe2x80x9cdie neckingxe2x80x9d is disclosed in U.S. Pat. No. 5,755,130 (Tung et al.), U.S. Pat. No. 4,519,232 (Traczyk et al.) and U.S. Pat. No. 4,774,839 (Caleffi et al.), each of which is incorporated by reference herein in its entirety. Die necking involves forcing an open end of a can body into a die so that an inwardly tapered surface of the die permanently deforms the open end inward. Another type of necking operation is known as xe2x80x9cspin necking.xe2x80x9d Spin necking involves reducing the diameter of a can end by pressing the can end against a rotating tool.
A variety of machines have been developed for necking can ends. For example, FIGS. 1-3 depict a five-stage necking machine 12 adapted to perform a die necking process on a can body 2. (The can body 2 is depicted as entering the necking machine 12 in FIG. 1, with the direction of travel of the can body 2 denoted by the arrow 4).
Necking machines such as the necking machine 12 are available from Belvac Production Machinery of Lynchburg, Va., as model 595 6N/8. A necking machine substantially similar to the necking machine 12 is described in detail in U.S. Pat. No. 6,085,563 (Heiberger et al.), which is incorporated by reference herein in its entirety.
The necking machine 12 comprises a unitary base 5, and a bearing plate 9 fixedly coupled to a top surface of the base 5. The base 5 forms an enclosure adapted to contain a vacuum generated by an external source (not pictured). In other words, the base 5 has a sealed internal volume 35 adapted to contain an externally-generated vacuum (see FIG. 2). (In other words, the internal volume 35 of the necking machine 12 functions as a vacuum chamber.)
Three pipes 58 extend into and out of the base 5 by way of through holes formed in end plates 5a of the base 5 (see FIG. 3). The uppermost pipe 58 conveys vacuum, and the remaining pipes 58 convey positive or pressurized air to the necking machine 12.
The necking machine 12 further comprises an input chute 7 and an input module 11. The input module 11 comprises a feed wheel 6 having a plurality of pockets 25 formed therein (see FIG. 1). The pockets 25 are each adapted to receive the can body 2 from the input chute 7. The feed wheel 6 rotates in a counterclockwise direction (from the perspective of FIG. 1).
The can body 2 is retained in one of the pockets 25 by a vacuum force. More particularly, a port is defined in the surface that defines each of the respective pockets 25. The port communicates fluidly with the internal volume 35, of the base 5 by way of a hose 48 coupled to the internal volume 35 and a rotary manifold (not shown) within the feeder wheel 6. The vacuum is transmitted to the port by the hose 48 and the rotary manifold, and generates a suction force that retains the can body 2 in the pocket 25.
The necking machine 12 further comprises a first, second, third, fourth, and fifth necking module, respectively designated 17a, 17b, 17c, 17d, 17e. The necking modules 17a, 17b, 17c, 17d, 17e each comprise a necking station, respectively designated 16a, 16b, 16c, 16d, 16e (see FIG. 1). The necking stations 16a, 16b, 16c, 16d, 16e are adapted to incrementally reduce the diameter of an end of the can body 2, as explained below. Each of the necking stations 16a, 16b, 16c, 16d, 16e rotates in a clockwise direction (from the perspective of FIG. 1).
The necking stations 16a, 16b, 16c, 16d, 16e each have a plurality of pockets 27 formed therein. The pockets 27 are adapted to receive the can body 2. The can body 2 is retained in the pockets 27 by mechanical guides (not shown), and by the necking process that is performed by the necking stations 16a, 16b, 16c, 16d, 16e. 
The feed wheel 6 carries the can body 2 through an arc of approximately 210 degrees, and deposits the can body 2 into one of the pockets 27 of the necking station 16a. Using techniques well known in the art of can making, an open end of the can body 2 is brought into contact with a die (not shown) in the necking station 16a. The necking station 16a carries the can body 2 through an arc of approximately 180 degrees, along the top portion of the necking station 16a. The noted contact between the can body 2 and the die slightly reduces the diameter of the open end of the can body 2. (The diameter -reduction process, as noted above, is commonly referred to as xe2x80x9cnecking.xe2x80x9d)
The necking machine 12 also comprises first, second, third, and fourth intermediate, or transfer, modules, respectively designated 19a, 19b, 19c, 19d. The transfer modules 19a, 19b, 19c, 19d each comprise an intermediate, or transfer, wheel, respectively designated 18a, 18b, 18c, 18d (see FIG. 1). The transfer wheels 18a, 18b, 18c, 18d each rotate in a counterclockwise direction.
Each of the transfer wheels 18a, 18b, 18c, 18d has a plurality of pockets 29 formed therein. The pockets 29 are adapted to receive the can body 2. The can body 2 is retained in the pockets 29 in a manner substantially identical to that described above with respect to the input module 11 and the pockets 25.
The transfer modules 19a, 19b, 19c, 19d are each located between a respective pair of the necking modules 17a, 17b, 17c, 17d, 17e, as depicted in FIGS. 1 and 2. The necking station 16a deposits the can body 2 into one of the pockets 29 of the transfer wheel 18a after the necking station 16a has reduced the diameter of the end of the can body 2 as described above.
The transfer wheel 18a carries the can body 2 through an arc of approximately 180 degrees, and deposits the can body 2 into one of the pockets 27 of the necking module 16b. The necking module 16b further reduces the diameter of the end of the can body 2 in a manner substantially identical to that noted above with respect to the necking station 16a. 
The can body 2 is subsequently transferred between the necking stations 16c, 16d, 16e by the transfer wheels 18b, 18c, 18d, in a manner substantially identical to that described above with respect to the transfer wheel 18a. The diameter of the end of the can body 2 is further reduced by the necking stations 16c, 16d, 16e, in a manner substantially identical to that noted above with respect to the necking station 16a. 
The necking machine 12 further comprises a discharge module 21 located immediately downstream of the necking module 16e, and a discharge chute 22. The discharge module 21 comprises a discharge wheel 20 having a plurality of pockets 31 formed therein. The pockets 31 are adapted to receive the can body 2 from the necking module 16e. The can body 2 is retained in the pockets 31 in a manner substantially identical to that described above with respect to the input module 11 and the pockets 25.
The discharge wheel 20 rotates in a counterclockwise direction. The discharge wheel 20 carries the can body 2 through an arc of approximately 180 degrees, and deposits the can body 2 in the discharge chute 22. The discharge chute 22 subsequently guides the can body 2 out of the necking machine 12.
The input feed wheel 6, the transfer wheels 18a, 18b, 18c, 18d, and the discharge wheel 20 are each driven by a respective shaft 32 that, in turn, is driven by a corresponding gear 24 (see FIGS. 2 and 3). The necking stations 16a, 16b, 16c, 16d, 16e are each driven by a respective shaft 8 that, in turn, is driven by a corresponding gear 24 (see FIGS. 3 and 4C).
The gear 24 associated with the transfer module 19c is coupled to and driven by a motor 28 by way of a gear box 26 and a drive belt 30 (see FIG. 3, the motor 28, gear box 26, and drive belt 30 are not shown in FIG. 2, for clarity). The motor-driven gear 24 drives the two immediately adjacent gears 24, which, in turn, drive the next gears 24, and so on.
The drive shafts 32, 8 are each rotatably coupled to bearings 33 mounted on the bearing plate 9 (see FIG. 3). The necking stations 16a, 16b, 16c, 16d, 16e each support an end of their associated drive shaft 8 by way of a respective bearing housing 15 (see FIG. 4C). The transfer modules 19a, 19b, 19c, 19d each support an end of their associated drive shaft 32 by way of a respective bearing housing 13 (see FIG. 3).
Conventional fixed-base necking machines, in general, comprise no more than nine stages. Contemporary can necking operations, however, are often performed in more than nine stages. Ten or more necking stages are often needed to achieve the substantial reductions in diameter sought by many can manufacturers. Hence, two or more necking machines are often coupled in some manner to achieve the required number of necking stages for a particular application.
Multiple necking machines may be coupled using a conveyor that transports a partially necked can body from the first, or upstream, necking machine to the second, or downstream, necking machine. The second necking machine, upon receiving the can end, performs further necking operations thereon.
The use of a conveyor to couple upstream and downstream necking machines has several drawbacks. For example, conveyors may damage a can body during conveyance thereof, and can become jammed by the can bodies being conveyed thereon. Conveyors also require that the upstream and downstream necking machines be spaced apart to absorb can build-up caused by variations in speed between the upstream and downstream necking machines, thereby increasing the amount of floor space required by the necking machines.
Alternatively, multiple necking machines may be coupled using a transfer wheel, or bridge, similar to the transfer wheels 18a, 18b, 18c, 18d, positioned between the upstream and downstream necking machines. The transfer wheel receives a partially necked can body from the discharge module of the upstream necking machine, and transfers the can body to the input module of the downstream necking machine. The use of a transfer wheel in this manner is disclosed in U.S. Pat. No. 6,085,563.
The use of a transfer wheel to couple two or more necking machines has proven successful. The cost of procuring, installing, and operating this additional component, however, can be substantial. Moreover, the transfer wheel requires floor space in the manufacturing plant. This characteristic represents a disadvantage, as floor space in such plants is often limited.
Moreover, the can bodies can shift along their respective longitudinal axes within the pockets of the transfer wheel. Such shifting can cause the can bodies to be improperly positioned in the downstream necking module, thus leading to jamming of the necking module.
Consequently, a need exists for a method for coupling two or more necking machines without the use of a conveyor or a transfer wheel.
A preferred method is provided for closely coupling a first and a second necking machine each comprising a base, a bearing support plate fixedly coupled to the base, an input module comprising an input feed wheel adapted to receive a can body and a drive gear rotatably coupled to the bearing support plate, a necking module comprising a necking station adapted to reduce a diameter of an end of the can body and a drive gear rotatably coupled to the bearing support plate, and a discharge module comprising a discharge wheel adapted to discharge the can body from the necking machine and a drive gear rotatably coupled to the bearing support plate.
A preferred comprises removing the input module from the second necking machine, removing an end portion of the bearing support plate and an end portion of the base of the second necking machine, and fixing a cover plate to the base of the second necking machine.
A preferred method further comprises positioning the first and second necking machines end to end so that the drive gear of the discharge module of the first necking machine meshes with the drive gear of the necking module of the second necking machine and the necking module of the second necking machine is adapted to receive the can body from the discharge module of the first necking machine.
Another preferred method for closely coupling the first and second necking machines comprises removing the discharge module from the first necking machine, removing an end portion of the bearing support plate and an end portion of the base of the first necking machine, and fixing a cover plate to the base of the first necking machine.
A preferred method also comprises positioning the first and second necking machines end to end so that the drive gear of the necking module of the first necking machine meshes with the drive gear of the input module of the second necking machine and the input module of the second necking machine is adapted to receive the can body from the necking module of the first necking machine.
Another preferred method is provided for closely coupling a first and a second necking machine each comprising a base, a bearing support plate fixedly coupled to the base, an input module adapted to carry a can body in a downstream direction and comprising a drive gear rotatably coupled to the bearing support plate, a necking module located downstream of the input module, adapted to reduce a diameter of an end of the can body, and comprising a drive gear rotatably coupled to the bearing support plate, and a discharge module located downstream of the necking module, adapted to discharge the can body in the downstream direction, and comprising a drive gear rotatably coupled to the bearing support plate.
A preferred method comprises removing the input module from the second necking machine, removing a portion of the bearing support plate and a portion of the base of the second necking machine located upstream of the of the necking module of the second necking machine, and fixing a cover plate to the base of the second necking machine.
A preferred method also comprises positioning an upstream end of the second necking machine adjacent a downstream end of the first necking machine so that the drive gear of the discharge module of the first necking machine meshes with the drive gear of the necking module of the second necking machine and the necking module of the second necking machine is adapted to receive the can body from the discharge module of the first necking machine.
Another preferred method for closely coupling the first and second necking machine comprises removing the discharge module from the first necking machine, removing a portion of the bearing support plate and a portion of the base of the first necking machine located downstream of the of the necking module of the first necking machine, and fixing a cover plate to the base of the first necking machine.
A preferred method also comprises positioning an upstream end of the second necking machine adjacent a downstream end of the first necking machine so that the drive gear of the necking module of the first necking machine meshes with the drive gear of the input module of the second necking machine and the input module of the second necking machine is adapted to receive the can body from the necking module of the first necking machine.